/**
 * AjLog - The AspectJ based logging facade
 *
 * Copyright (C) 2009 - 2010, Marko Umek. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.ajlog.core.message.segment;

import java.util.Properties;

/**
 * SystemPropertiesMessageSegement is responsible for handling the System
 * properties within the message.
 * 
 * @author Marko Umek
 * 
 * @see System#getProperties
 */
public class SystemPropertiesMessageSegement extends AbstractConstantMessageSegement {

    private final String constantString;

    /**
     * Constructor
     * 
     */
    public SystemPropertiesMessageSegement(final String propertyName, final String defaultValue) {
        this.constantString = System.getProperty(propertyName, defaultValue);
    }

    /**
     * Constructor
     * 
     */
    public SystemPropertiesMessageSegement(final String propertyName) {
        final Properties properties = System.getProperties();
        if (properties.contains(propertyName)) {
            this.constantString = properties.getProperty(propertyName, "(null)");
        }
        else {
            this.constantString = properties.getProperty(propertyName, "(not set)");
        }
    }

    /* (non-Javadoc)
     * @see org.ajlog.core.message.segment.IMessageSegment#buildConstantMessage(java.lang.StringBuilder)
     */
    public void buildConstantMessage(final StringBuilder messageBuilder) {
        messageBuilder.append(this.constantString);
    }

}
